Monthly Archives: May 2015

Ribs on the wings

I had a productive day at the shop… too bad it wasn’t so productive plane-wise!

A buddy moved to Seattle and left a bunch of household goods and books in the garage (at one point, his car was in the garage as well.  He’s shipping it out on Amtrak this Wednesday (yay!), but I had to rebox it all (boo!), but now I have a lot more room to work (yay!). IMG_1732

With that out of the way (3.5 hours of re-boxing), I started back in on the wings.  The first step is to bolt most (but not all) of the ribs onto the wings.  I had marked all the bolts, but in the end, it didn’t help much.  It was hard to sort into the correct wing pile due to poor penmanship and even when I did, the bolts kept rolling around.

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In the end, it was much easier to just sort by size.

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Even without measuring, it was easy to distinguish the AN3-5A, from the 6A’s and 7A’s.  A quick check of the bolt diagram made it clear that I had sorted the bunches correctly.  Alas, I started on the wrong rib (discovered about 4 ribs in), so I had to pull them out and shift them over (luckily, I had not torqued the nuts on yet).

The instructions say to leave several bolts nut-free.  It doesn’t say much except that you’ll “have to push them out of the way to rivet.”  The instructions make it seem like its’ for the AN4 rivets, but in fact it is for the AN3 flush rivets later on.

Torquing the nuts went pretty quickly.  My wife even helped with a couple when she came by for lunch.

After lunch (determined not to let my lunch distraction bug-a-boo take hold) I took the left wing off of the cradle to get better access to the AN4 rivets.  I clamped the spar on one end and clamped a block on the other.  It held the spar securely and I shot very good rivets (just one small smiley).

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A nice clean row of rivets!

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I shot these all with manufactured heads on the forward side of the spar.  The tungsten bucking bar worked really well here.

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The next step was to add some flush rivets to hold on 7 of the ribs.  At first it didn’t make sense, but then I realized that this was where the fuel tank would attach.  The flush rivets will sit underneath the fuel tank skin (so of course their flush and done now!).  I was able to squeeze these with my longeron yoke (working around the aforementioned bolts and nuts).

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I was eager to get on to the right wing, but I had to do some prep work for a talk on riveting that I’m giving Tuesday night at the flying club meeting.  I’m doing some riveting demos and wanted some small pieces that people could try their hand at.  So, I cut up some left-over J-stiffener and some scrap bits that were trimmed off of some rear fuselage parts.  I also made a small back-rivet demo piece.   Hope the talk goes well.

I’m not sure when I’ll work on the plane again.  We’re taking a two+ week European vacation (I know, life is tough) and the day after we fly back, I’m flying on to Chicago where I’m starting a new job.  I’ll be commuting back and forth for a while (oh, those frequent flyer miles!) before settling there full time.  Moving the project will certainly be exciting!

I’ll have to try and dig up some local builders as I rebuild my flying hobby there.  I’m already looking at the Chicago Glider Club for a new rating!


Riveting stuff onto the wing ribs

Lots of rivets today… I didn’t get everything done that I hoped for, but still, riveting is more fun than part prep!

First up was riveting the flap hinge brackets onto a couple of the ribs.  These had already been match drilled and deburred in a previous step.  16 rivets per flap hinge.  4 hinges.  64 rivets.  I got all of these using my longeron yoke (since there are flanges on each side).  They came out great!  No smileys.  No heads lifting up.  None to drill out.

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Next up were the torque tube support brackets.  These go on the most inboard ribs of each wing.  The left and right are mostly mirror images of each other, but the size of each bracket is a little different.  I had marked them carefully during their prep, so not an issue.  The first bracket went together perfectly!  I used my 4″ no-hole yoke.  I was able to squeeze all the rivets (thus avoiding the dreaded offset rivet set!).

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I did the second bracket after lunch.  I make a lot of mistakes after lunchtime (my wife stops by for lunch after the gym and is clearly a big distraction from plane building, but I’ll keep her anyway!)

This mistake was easy to spot.  I put in a 470 4-4 instead of a 470 4-5 rivet.  It was hugely obvious right after I squeezed it.  The shop head was way too small!  I had to fire the compressor up just to drill out this one rivet.

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I’m giving a presentation on riveting to my flying club in a couple of weeks, so this was a great chance to show how to remove a rivet.  It came out very cleanly.

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It was a beautiful day to go flying (isn’t every day?).  I flew the retract Arrow up to Connecticut to get its oil changed, so the flight counted as club ferry time (as in FREE!).  I’m feeling pretty comfortable driving the Arrows now.  Which is good, because we’re getting a lot of new low-time members who are all flying the Archers.  More planes is more better!

The next step is to rivet and bolt the ribs onto the spars.  That will end Section 14.  I’ll hold off riveting this bracket onto its rib so that I can use it for a demo at the club meeting in a couple of weeks, but I should be on to Section 15 when I get back from vacation and my first couple weeks on my new job in Chicago.